Can plastic compost bins leach toxins?

mrs_tlcJuly 4, 2010

I guess the message title says it all. With all of the concern of BPA and plastics acting like estrogen in our bodies, is it safe to use a plastic compost bin or could it leach toxins into the compost???

There is some speculation they might and there is some, emphatic, denial that they would, but I have not seen anything that really tells me one way or the other. Keep in mind that it took some 40 years after the toxicity question about CCA PT wood was first raised before there was actual concern enough to look and find there was.

I am confident that plastic compost bins release chemicals to the air, and also to the compost they contain. But I'm not sure that the chemicals persist. They might be consumable, something else for the microbes to digest. Trying to answer this question sounds like a research project.

It is known that some plastics can release, if not toxins at least stuff we do not wnat, substances under some circumstances. Some release toxins inot foods when microwaved, some release toxins into the drinking liquid they contain, but not enough is known about many others.
As a rule plastics are made from non sustainable materials anywya, so we should really rethink using any at all.

I'm finding it's pretty hard to avoid using plastic, so I'm trying to use the types I think are the least likely to be a problem. I avoid pvc/vinyl if at all possible. But what about the plastic they make black poly pipe out of? Does anyone know how safe that is? I'm hoping it's better than pvc. And I'm planning to make some manure tea in a garbage can lined with a plastic bag. I'm hoping the toxic stuff will be negligible. Maybe I'll be able to find something better for next year. But this year, I just have to use what I already have, or what's cheap.

Are you talking about ABS? It's another thermoplastic material; the MSDS sheets are almost identical. It's typically used for waste lines and in other applications where the water is not very hot. It's more rigid and brittle than PVC but not in a huge way. Typically PVC only has phthalates in it if it is desired to be flexible, like vinyl purses and flex-PVC hose. Rigid PVC used in plumbing does not contain phthalates/BPA. Neither does ABS.

I was reading, in The Green Pharmacy, not so long ago, that phytoestrogens are completely different than toxic chemicals that mimic estrogens.

"The soy supporters tout soybeans because they are high in two estrogen-like plant compounds, genistein and daidzein. Both of these phytoestrogens prevent your body from taking up the more harmful forms of estrogen circulating in your blood. They take the place of that estrogen, binding to your cells' estrogen receptor sites and preventing more harmful estrogens from binding to the same receptors. Significantly, they also protect the body from pollutants that chemically mimic estrogen.

The soy supporters are right. Soy is high in genistein and daidzein, but lots of other beans are also quite high in genistein, which appears to be the more active of the two phytoestrogens." ~James A. Duke, The Green Pharmacy

I think heat makes the toxins release. That's why we're told to not use plastic in the microwave to heat up food. Since compost heats up as it "works", wouldn't that mean the toxins would release into your compost? I vermicompost in plastic bins and they do fine. Earthworms are very sensitive to invironmental toxins, so maybe they're not affected because the bin's not heating up, thereby not releasing the toxins. Can't seem to avoid the plastic in our lives!

Any plastics can release toxins under heat but it's a matter of degree. I doubt the small amount of toxins released by a compost bin will even be noticed. It's all but impossible to avoid plastics in the modern world.